Entity Framework Extensions Ignore OnMergeMatched AndOneNotCondition Expression

Description

The IgnoreOnMergeMatchedAndOneNotConditionExpression is the inverse of MergeMatchedAndNotConditionExpression

• The MergeMatchedAndNotConditionExpression allows you to perform only the UPDATE in the BulkMerge if the specified property value is not equal to the database value.
• So by default, all columns are included in IgnoreOnMergeMatchedAndOneNotConditionExpression but not the one you choose to ignore.

The following example updates all those records in which the ModifiedDate property is not equal to database value. It ignores the properties specified in IgnoreOnMergeMatchedAndOneNotConditionExpression if their value is equal to the database or not.

using (var context = new EntityContext())
{
    var customers = context.Customers.ToList();
    customers.ForEach(x => { x.Name += "_Updated"; x.Description += "_Updated"; x.IsActive = false; });
    customers.Take(2).ToList().ForEach(x => { x.ModifiedDate = DateTime.Now; });

    context.BulkMerge(customers, options => 
    {
        options.IgnoreOnMergeMatchedAndOneNotConditionExpression = c => new 
        {
            c.Name, 
            c.Description, 
            c.CreatedDate, 
            c.IsActive 
        };
    });
}

Try it: EF Core | EF6

• It will update all the records except for the last one.
• The ModifiedDate property is only updated for the first two records and not for the last record.